Plastic pull tab to metal tear strip connection with mechanical interlock



July 20, 1965 J. HENCHERT 3,195,767

PLASTIC PULL TAB TO METAL TEAR STRIP CONNECTION WITH MECHANICAL INTERLOGK Original Filed Feb. 10, 1961 INVENTOR Jouu HENCHEET ATTORNEYS United States Patent 9 PLASTI C PULL TAB TD METAL TEAR STRIP CON- NEQTIGN VilTH h iECHANlCAL HNTERILQQK l'ohn Henchert, Oak Park, BL, assignor to tjontinentai Ian @empany, Inc, New York, N.Y., a corporation of New Yori Original application Feb. 16, 1961, 5361'. No. 88,473, new Patent No. 3,1d1fi6, dated Get. 6, B64. Divided this application June E9, 1963, Ser. No. 239,070

3 Claims. (Q3. Hit-54) This application is a division of my copending application Serial No. 88,473, filed February 10, 1961.

This invention relates in general to new and useful improvements in means for opening containers, such as cans, and more particularly is directed to a novel tear strip arrangement for containers including metal can ends wherein a container may be opened by merely grasping a pull tab attached to a tear strip and removing the tear strip to thereby remove a panel of the container.

On of the primary objects of this invention is to provide a novel tear strip and pull tab combination wherein the pull tab is firmly anchored to one end of the tear strip and is of a greater width than the tear strip whereby the pull tab rests upon the associated container member on opposite sides of the tear strip to reinforce the tear strip at its starting end to eliminate the accidental rupture of the container member at the starting end of the tear strip.

Another object of this invention is to provide a novel tear strip and pull tab arrangement wherein the pull tab is provided with an end which is merely passed through an opening in the starting end of the tear strip and is thus interlocked with the tear strip, with the mechanical connection between the tear strip and the pull tab being sufliciently great to prevent the accidental removal of the pull tab from the tear strip during a tear strip removal operation.

A still further object of this invention is to provide a novel mechanical connection between a plastic pull tab and a metal tear strip wherein the tear strip is provided with an opening into which a plug portion of the pull tab is snapped and the connection between the plug portion and the adjacent metal of the tear strip being such that as the pressure on the plug portion for removal thereof is increased, the gripping of the plug by the metal of the tear strip is likewise increased to prevent the separation of the tear strip and the pull tabv Still another object of this invention is to provide a novel plastic pull tab and metal tear strip connection wherein the metal tear strip is provided with an opening through which a plug portion of the pull tab is passed, and after which the plug portion is curled to provide the necessary mechanical interlock between the pull tab and the tear strip.

This invention also proposes to provide means to facilitate the starting of the tearing of a tear strip from the adjacent metal whereby the tear strip is provided with a generally semi-circular end portion which is scored more deeply than side edge portions of the tear strip, whereby a lesser starting force is required to rupture the tear strip along the score lines.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a perspective view of an upper portion of a can having a metal can end which is provided with a tear strip and pull tab in accordance with this invention.

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FIGURE 2 is a perspective view similar to FIGURE 1 and shows the tear strip partially removed.

FIGURE 3 is an enlarged fragmentary perspective view showing further the general details of the tear strip and pull tab combination.

FIGURE 4 is an enlarged fragmentary vertical sectional view taken along the line 44 of FIGURE 3, and shows the specific details of the connection between the pull tab and tear strip.

FIGURE 5 is an enlarged fragmentary transverse vertical sectional view taken along the line 55 of FIGURE 3 and shows further the details of the connection between the pull tab and tear strip, including the fact that the pull tab overlies the metal can end on opposite sides of the tear strip to prevent the accidental rupturing of the can end along the outline of the tear strip by a downward pressure.

FIGURE 6 is a fragmentary plan view showing the general outline of the tear strip at the starting end thereof and the formation of the score lines defining the same.

FIGURE 7 is an enlarged fragmentary vertical sectional view taken along the line 7-7 of FIGURE 6 and shows the specific arrangement of the scores in the various portions of the metal can end along the outline of the tear strip.

Reference is first made to FIGURES 1, 2 and 3 wherein there is illustrated a conventional type of can which is generally referred to by the numeral 2%, and which includes .a can body 211 and a can end 22. The can end 22 is preferably formed of a light gauge metal and it is desirable that the metal be easily rupturable. As a result, normally the can end 22 will be formed of aluminum, although the usual metals employed in the making 'of the can ends may be utilized. The can end 22 is secured to the can body 21 by a conventional seam 23. The can 2i) is illustrated and described only to set forth one environment of the invention. The present invention is not restricted to cans, but may be used in all types of containers, etc., where it is desired to remove a portion thereof without utilizing any opening equipment, such as a can opener in the case of a can.

Reference is now made to FIGURE 3 in particular, wherein the can end 22 is illustrated as having a circumferential tear strip 24 which is defined by a pair of score lines 25, 26 with the score line 25 being disposed outermost and being disposed adjacent the seam 23 so that when the tear strip 24 is removed, substantially the entire can end 22 within the'seam 23 will be removed. The score lines 25, 2e are disposed generally in concentric relation for the most part of their lengths and the score line 26 generally defines an inner panel 27.

The starting end of the tear strip 24 is provided with a pull tab, which is generally referred to by the numeral 23. The pull tab 28, as is best shown in FIGURES 4 and 5, is formed of a resilient deformable plastic.

The starting end of the tear strip 24 is provided with an opening 29 therethrough defined by an annular flange 3d. The flange 3t} first extends downwardly and inwardly and is then turned inwardly at a greater angle, as at 31.

The pull tab 28 has a plug portion 32 which is of a hollow or tubular construction, as is clearly shown in FIGURES 4 and 5. The plug portion 32 is passed through the opening 29, and after it is passed therethrough, the plug portion 32 is curled upwardly, as at 33, around the flange 3% to provide a mechanical interlock therewith. In this manner, the pull tab 28 is firmly connected to the tear strip 24 in a manner wherein an effective seal between the pull tab 28 and the tear strip 24 is provided, thus assuring that no leak will occur through the opening 29 even though the can Ztl is utilized for the purpose of packaging products under pressure.

downward deflecion of the starting end of the tear strip 24 in the event a pressure is exerted either on the pull tab 28 or directly on the tear strip 24. i

Referring once again to FIGURE 4 in particular, it will be seen that the pull tab 28 has an elongated body portion 34 which is thinner than that portion of the pull tab from which the plug portion 32 projects. gated body portion 34 is relatively resilient and in order to facilitate grasping of the pull tab to exert'a tear strip tearing and removal force thereon, the body portion 34 is provided adjacent the end thereof remote from the plug portion 32 with an upper transverse rib 35 and a lower transverse rib 36. The ribs 35 and 36 are preferably aligned, and the rib 36 is of a thickness to sit on the upper surface of the' can end 22 in the normal at rest position of'the pull tab 28.

. Reference is now made to FIGURES 6 and 7, wherein the details of the score lines defining the various tear strips at the starting end of each tear strip, are shown. For identification purposes only, the partial can end illustrated in FIGURE 6 will be considered to be the can end 22, and the tear strip 24. As was previously described, the tear strip 24 is defined by a pair of score lines 25, 26. As is best illustrated in FIGURE 7, these score lines 25,26 are relatively shallow. The score lines 25 and 26 will preferably be of a depth so that the remaining metal to be torn in the removal of the tear strip 24 will have a thickness of 0.003 inch. The ends of the score lines 25, 26 are connected together by a generally semi-circular score line 102 which has a greater base width and is 'of a greater depth, as is best illustrated in FIGURES 6 and 7. The depth of the score line 102 will be such that in most instances, the remaining thickness of metal to be torn will range between 0.001 inch and 0.0015 inch. By making the score line 102 much deeper than the score lines 25, 26, it will be readily apparent that a sharp upward pull on the starting end of the tear strip 24 by means of the pull tab 28 will result in the rupturing of the metal of the can end 22 along the score line 102. Once the initial rupturing has been accomplished, the tear strip 24 may be removed by continuously exerting an upward pull thereon with the tear strip 24 being torn from the can end 22 along the tear lines 25, 26.

we The advantage of the relatively deep score line 102 coupled with the supporting feature of the individual pull tab is obvious. Applicant has made the initially torn portion of the can end of suflicient weakness to facilitate the easeof tearing the starting end of the tear strip therefrom. On the other hand, by making each pull tab of a suflicient width to engage the can end outwardly of the tear strip, the tear strip is prevented from deflecting inwardly due to any accidental force exerted thereon, whereby the can 20 would be opened prematurely.

From the foregoing, it will be seen that novel and advantageous provision has been made for carrying out the desired end. However, attention is again directed to The elonthe fact that variations may be made in the examples of the invention disclosed herein without departing from the spirit and scope of the invention, as defined in the appended claims.

I claim:

7 1. A tear strip assembly comprising a metal tear strip having a starting end, and a plastic pull tab, said tear strip starting end having a flanged opening therethrough defined by a flange, said pull tab having a plug portion extending through said tear strip opening and being reversely curled around said flange and substantially encasing said flange with said plug portion sealing the opening, said plug portion being tubular to facilitate the curling of the lower part thereof, and said flange having an inwardly directed lower part whereby an upward pullon said plug portion will result in an inward deflection of said flange and a firmer gripping of said plug portion.

2. A tear 'strip assembly comprising a panel, a tear strip defined in said panel'by. spaced weakening lines in said panel, said tear strip havinga starting end defined by portions of said weakening lines of greater weakness to facilitate the initial rupture of said panel, and a pull tab overlying and connected to said tear strip starting end for facilitating the removal of said tear strip,'said pull tab being of 'agreater width than the underlying portion of said tear strip and resting on said panel outwardly of said tear strip to resist accidental rupturing of said panel by inward displacement of said tear strip starting end, said tear strip having an opening therethrough and said pull tab having a plug portion extending through the tear strip opening and locking behind said tear strip to both directly seal said opening and secure said pull tab to said tear strip, said tear strip opening being defined by a downwardly directed flange and'said plugportion having a lower part engaged behind said flange, said plug portion having a lower part reversely outwardly curled to generally encase'said flange, said plug portion being tubular to facilitate the curling of thelower part thereof, and said flange having an inwardly directed lower part whereby an upward pull on said plug portion will result in an inward deflection of said flange and a firmer gripping of said plug portion. r

'3. The tear'strip assembly of claim 1 wherein said pull tab is in the form of an elongated strip having a thick attaching portion from which said plug portion projects and a thinner grip portion, said grip portion hav ing transverse ribs extending thereacross to facilitate gripping thereof.

References Qited by the Examiner UNITED STATES PATENTS 2,029,329 2/36 Ljungstrom et a1; 220-52 2,741,396 4/56 Lobl 220 2,978,140 4/61 Walsh.

3,083,858 4/ 63 Biedenstein 220-27 TI-IERON E. CONDON, Primary Examiner, 

